Conventionally, there are known drive units driven by taking advantage of the properties of a shape memory alloy, that is, the properties in which the shape memory alloy shrinks by heat of a certain temperature (operation temperature) or higher generated by passing an electric current therethrough even after being deformed by force (for example, refer to Patent Literature 1).
This drive unit is provided with an insulating base member having an operation base having one or more operation recesses in its top surface, and a movable member that is opposite to the base member and has operation projections to be inserted into the operation recesses in its opposed surface. A shape memory alloy material, which shrinks by heat generated by passing an electric current therethrough, is disposed between the opposed surfaces in such a manner as to be curved by following the operation recesses of the base member. Both ends of the shape memory alloy material are connected to connection terminals fixed to the base member.
In this drive unit, the shape memory alloy wires shrink by super elasticity when heated to the certain temperature or higher by passing the electric current through the shape memory alloy wires, so that the shape memory alloy wires push the movable part relatively in a direction away from the base member. When lowering the temperature of the shape memory alloy wires to the certain level or lower by canceling the energized state thereof, the shape memory alloy wires return to their original positions, and thus each of the shape memory alloy wires returns to the curved shape (shape in a non-energized state).
In this drive unit, the base member is fixed to a support member that is composed of a mounting board, an electronic equipment case, or the like, and the movable member is allowed to be in contact with or fixed to a device to be driven such as the electronic equipment case, so that a driving force of the drive unit, which is supported by the support member, is transmitted to the device to be driven.
On the other hand, as for mounting of this type of drive units, in addition to a structure of mounting the connection terminals fixed to the base member on the mounting board by surface mounting, there is known a structure for mounting the drive unit on the support member such as the mounting board without using soldering in which, just as with mounting of a general electronic component, clip-shaped terminals, which are formed as with fuse clips by pressing a conductive metal plate, are used and fixed to desired positions of the support member such as the electronic equipment case and the pair of clips made of spring nippers catch the connection terminals fixed to the base member (for example, refer to Patent Literature 2).
As this type of structure for mounting the electronic component on the support member without using soldering, there is known another structure in which cantilever spring attachment claws are formed in the support member such as the electronic equipment case so as to face in an entire height direction of the electronic component, and the attachment claws are engaged with a top end edge of the electronic component to allow mounting with a single motion (for example, refer to Patent Literature 3).